Host sharing by the honey bee parasites Lotmaria passim and Nosema ceranae

Abstract

The trypanosome Lotmaria passim and the microsporidian Nosema ceranae are common parasites of the honey bee, Apis mellifera, intestine, but the nature of interactions between them is unknown. Here, we took advantage of naturally occurring infections and quantified infection loads of individual workers (N = 408) originating from three apiaries (four colonies per apiary) using PCR to test for interactions between these two parasites. For that purpose, we measured the frequency of single and double infections, estimated the parasite loads of single and double infections, and determined the type of correlation between both parasites in double infections. If interactions between both parasites are strong and antagonistic, single infections should be more frequent than double infections, double infections will have lower parasite loads than single infections, and double infections will present a negative correlation. Overall, a total of 88 workers were infected with N. ceranae, 53 with L. passim, and eight with both parasites. Although both parasites were found in all three apiaries, there were significant differences among apiaries in the proportions of infected bees. The data show no significant differences between the expected and observed frequencies of single‐ and double‐infected bees. While the infection loads of individual bees were significantly higher for L. passim compared to N. ceranae, there were no significant differences in infection loads between single‐ and double‐infected hosts for both parasites. These results suggest no strong interactions between the two parasites in honey bees, possibly due to spatial separation in the host. The significant positive correlation between L. passim and N. ceranae infection loads in double‐infected hosts therefore most likely results from differences among individual hosts rather than cooperation between parasites. Even if hosts are infected by multiple parasites, this does not necessarily imply that there are any significant interactions between them.

Parasites of the genus Nosema, Crithidia and Lotmaria in the honeybee and bumblebee populations: a case study in India

“…Co-infection by N. ceranae and L. passim was also previously established in honeybee samples from Switzerland (Tritschler et al, 2017). Infection of both N. ceranae and C. mellificae parasites was described for honeybees from Belgian apiaries (Ravoet et al, 2013) (see Fig.…”

Impact of Mixed Infections of Gut Parasites Lotmaria passim and Nosema ceranae on the Lifespan and Immune-related Biomarkers in Apis mellifera

“…The thermal conditions were achieved with one cycle at 95 °C for 10 min, followed by 40 cycles at 95 °C for 15 s, 60 °C for 15 s and 72 °C for 15 s. A dissociation analysis was conducted after all of the amplifications were completed in order to detect the primer dimmers and the unspecific amplicons. Thus, the data regarding the pathogen loads were reported as cell or spore equivalents per bee, according to Tritschler et al [ 23 ]. Similarly, the data concerning immune-related genes were reported as relative expressions after normalization with an endogen gene (β-actin), according to Pfaffl [ 37 ].…”

“…However, there is no experimental evidence related to how a mixed infection of N. ceranae and L. passim could affect honey bee colonies. Some current reports have shown that mixed infections of these pathogens are not common (no more than 2%), in spite of the fact that they have been detected in high prevalence in single infections in honey bee hives [ 3 , 23 ], suggesting a possible competition between these two parasites. Furthermore, such mixed-species infections may influence the host immune responses, including genes that elicit antimicrobial peptides (AMPs) [ 7 , 16 ].…”

Pathogen Species Identification from Metagenomes in Ancient Remains: The Challenge of Identifying Human Pathogenic Species of Trypanosomatidae via Bioinformatic Tools

“…L. passim is the founding member of this genus ( Figure 1 ). This member of Crithidiatae is described as a common parasite of the honey bee Apis mellifera [ 25 ], which calls into question its presence in a human gut microbiome.…”